(1) Field of Invention
Pharmacies usually dispense a specific quantity of medicaments from bulk supply containers into smaller vials per each patient's prescription. These medicaments have to be precisely counted before being dispensed into vials. Several inventions have been made over the last few decades to enable quick and accurate counting of objects.
(2) Description of the Related Prior Art Including Information Disclosure
Retail pharmacies typically order large amounts of medicaments such as capsules and tablets from its suppliers. These medicaments are stored in bulk supply bins from where the correct number of medicaments are retrieved and counted by pharmacy staff when filling patients' prescriptions. Historically the medicaments had to be manually counted and dispensed into patient vials. Prior art indicates inventions exist that assist at automating the counting of discrete objects. All of these inventions have limitations.
Single Location Transmitter/Receiver Type Sensors:
In 1969 U.S. Pat. No. 3,618,819 was filed by Blackburn et. al. in which an electronic counter is described that utilizes a single optical sensor in order to optically count discrete components traveling in single file down a path or tube. The limitation of the Blackburn invention is that the objects have to pass by the sensor in single file to avoid counting errors. In the Blackburn et. al. patent no recommendation is provided to bring a disorderly flow of objects into single file in order for the objects to be accurately counted. In 1974 a patent was filed by Kirby (U.S. Pat. No. 3,789,194) which outlines an invention which attempts to address the problem created by objects traveling in a disorderly formation. When multiple objects pass by a single optical sensor while touching one another, or when one object is obscured by another object, the sensor will detect only one object. The Kirby (U.S. Pat. No. 3,789,194) invention attempts to overcome this counting problem by dispersing the disorderly flow of objects into as many as 16 separate paths. Each of these paths still however had only one optical sensor. Although the Kirby invention (U.S. Pat. No. 3,789,194) tends to distribute the disorderly flow of objects thereby reducing the chance of objects obscuring one another at the sensor, an inherent design flaw still remains. After the overall flow of objects are dispersed to multiple smaller paths, each individual smaller flow of objects are then once again constrained by a narrow path that passes by single discrete sensor, thus reintroducing the likelihood of objects obscuring one another as they pass through the narrow sensing region simultaneously.
Multiple Discrete Transmitter/Receiver Type Area Sensors:
In 1985 Harrsen et. al. (U.S. Pat. No. 4,675,520) filed a patent for an invention that describes an improved sensor type. The Harrsen et. al. patent comprises of a multitude of sensors arranged side by side such that the sensors would be able to detect multiple objects passing through the sensing region simultaneously provided that the objects were sufficiently laterally separated from one another, and that the objects do not obscure one another. The Harrsen et. al. invention introduced intelligence that previous single sensor type inventions lacked. As a result of the large sensing region described by Harrsen et. al. objects can pass through the sensing region laterally dispersed thereby reducing the chance that objects obscure one another. In 1991 two more patents were filed for inventions similar to the Hansen et. al. invention by Perozek et. al. (U.S. Pat. No. 5,317,645) and Ditman et. al. (U.S. Pat. No. 5,313,508).